Furcate contact

ABSTRACT

A furcate contact with at least two resilient contact arms. The contact has a body portion supporting the contact arms which converse toward one another adjacent the tip of the contact. Each contact arm is concavely arched perpendicular to its longitudinal axis and toward the opposite contact arm, the arched portion extending over essentially the entire length of each contact arm. In a preferred embodiment of the invention, each contact arm is divided into two arched contact fingers, each of the fingers being concavely arched perpendicular to its longitudinal axis and toward the opposite finger.

United States Patent [191 B'aueile et al.

[111 3,838,388 Sept. 24, 197 4 FURCATE CONTACT [75] Inventors: GerhardBiiuerle, Willsbach; Oswald Hiibner, Neuenstadt, both of [21] Appl. No.:362,913

[30] Foreign Application Priority Data May 31, 1972 Germany 2226561 [52]US. Cl 339/258 R [51] Int. Cl H0lr 13/12 [58] Field of Search 339/217,258, 259

[56] References Cited UNITED STATES PATENTS 1,963,061 6/1934 Bicknell eta1. 339/258 P 2,969,521 1/1961 Scoville 339/258 R 3,665,378 5/1972Hammell et a1 339/256 R FOREIGN PATENTS OR APPLICATIONS 953,626 12/1956Germany ..339/258R 1,461,938 11/1966 France... ..339/258R PrimaryExaminerJoseph H. McGlynn I Attorney, Agent, or Firm-N. Lesser;Frederick M. Arbuckle [5 7 ABSTRACT A furcate contact with at least tworesilient contact arms. The contact has a body portion supporting thecontact arms which converse toward one another adjacent the tip of thecontact. Each contact arm is concavely arched perpendicular to itslongitudinal axis and toward the opposite contact arm, the archedportion extending over essentially the entire length of each contactarm. In a preferred embodiment of the invention, each contact arm isdivided into two arched contact fingers, each of the fingers beingconcavely arched perpendicular to its longitudinal axis and toward theopposite finger. Y

2 Claims, 5 Drawing Figures SHEET NR 2 PAIENTEDSEPZMQM FIG. 2.

FIG. I.-

Pmminswww s wasee SHEET 2 OF 2 FURCATE CONTACT BACKGROUND OF THEINVENTION 1. Field of the Invention The field of art to which theinvention pertains is that of electrical connectors, and moreparticularly electrical receptacle-type contacts which are adapted toreceive blade or pin contacts for making electrical connection.

2. Description of the Prior Art Prior art furcate contacts generallyhave contact arms which are provided with opposing contact sectionsbiased toward one another. The contacting arms of the prior art contactshave a generally rounded, elongated appearance. Modifications of basicprior art receptacle-type contacts have been made for the purposes ofreceiving both plate-like and pin-like mating connector plug contacts.One such arrangement provides four protruding contact arms arranged inpairs, one above the other. Another known arrangement provides contactarms which are divided into two contacting fingers in side-by-siderelationship. In such arrangements, both plate-like and pin-likeconnector plug contacts can be received and guided into the receptacle.A variety of disadvantages of such prior art arrangements, however, havebeen demonstrated. The known configurations require careful insertion ofthe contact plugs, making it difficult to insert the plug in the centralposition of the receptacle. Further, close manufacturing tolerances inthe arrangement of the contact arms of the receptacle and the matingcontacts of the plug are encountered.

SUMMARY OF THE INVENTION It is an object of the present invention toprovide a furcate contact of the above-described type which is of simpledesign, facilitates the insertion of mating contacts, and assures goodelectrical connection.

In accordance with the invention there is provided a contact receptaclehaving contact arms which are concavely arched perpendicular to thelongitudinal axis and in the direction of the opposite contact arm, thearched portion extending over essentially the entire length of eachcontact arm.

One of the main advantages of utilizing concavely arched contact arms isthe fact that such construction results in improved rigidity of thecontact arms. Thus, with the same thickness of material for constructionof the contact, the length of the contact arms can be increased.Moreover, the contact pressure with the mating plug contact isincreased, thereby enhancing the electrical connection therebetween.These properties permit looser tolerances for the manufacture of thecontacts and hence reduce the production costs. At the same time, animproved receptacle contact results from the fact that they are notdamaged when the mating plug contact is inserted, even when the plug isnot exactly positioned in the center of the receptacle. Further, bothplate-like and pin-like mating contacts can be more readily insertedbetween the arched contact arms than with the flat contact arms of priorart devices.

Preferably, each of the opposing contact arms is formed having twoaxially aligned parallel concavities extending in the same direction,that is, toward the opposite contact arm. Such a configuration againresults in increased rigidity of the contact and improved the guidingeffect for receiving pin-like plug connector contacts.

In one embodiment of the invention, each contact arm is divided into twoconcavely arched contact fingers adjacent the free end of each of thecontact arms. The contact fingers are formed by providing a slitextending from the free end of the contact arm inwardly toward the bodyof the contact.

Since the increased rigidity of the contact arms and I contact fingersin accordance with the invention allows the application of increasedforces when mating contacts are inserted, the body portion of thecontact must also be sufficiently strong to accept such forces. Thus, ina modification of the furcate contact of this invention, the bodyportion is provided with a reinforcing depression or dimple extending inlongitudinal direction of the contact in the area of the contact joiningthe arms and the body portion.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 5 is a side elevation view of thefurcate contact of FIG. 4.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The furcate contact shown inFIGS. l3 is provided with a body portion having a U shaped carriermidsection 1 leading longitudinally into a flat resilient ridge 2leading to a connecting terminal end section 14 again having a U-shapedcross-section. Two contact arms 4 extend longitudinally from and arecarried by the carrier mid-section 1, the two arms 4 facing one another.One end of each arm 4 is integrally formed along a respective edge 4aand 4b of the body portion with the juncture of the edges of the uppersurface of the body portion lying in a common horizontal plane and onesurface of the integrally formed portion of each arm lies in arespective transverse plane extending along a respective edge 4a and 4bof the body portion. The arms 4 each has a cantilever portion extendingfrom the respective transverse plane and longitudinally from one end ofthe body portion toward each other arm to form cantilever spring arms tolocate the ends of the arms spaced from the body portion in adjacentpositions for receiving a male contact between 'the ends. The twocontact arms, beginning at the carrier mid-section l, extend inclinedtoward each other to the free end of the contact arms 4. Adjacent thefree end, the contact arms 4 are bent outwardly at an obtuse angle,thereby forming end sections 12 having internal camming surfaces l5adapted to readily position and easily accept a mating pin or plate typeplug contact.

As viewed in FIG. 2, each contact arm 4 may be provided with a slit 5which extends from the free end of the contact arm 4 toward the terminalend 14 over approximately one-third of the entire length of the contactarm 4. Each slit 5 divides the end section of the contact arm 4 into twocontact fingers 6 bent in a direction from each other with the anglebetween the fingers less than 180 to form guiding fingers for guiding apin contact member between the arms 4.

The cross-section of each contact arm 4 below the slit 5 is in the formof a pair of parallel and adjacent concavely arched portions 7 which arearched perpendicular to the longitudinal axis of each of the fingers 6.Each of the arched portions 7 has a width approximately equal to that ofa contact finger 6. The concave portions extend over substantially theentire length of the contact arm 4 and reach the area of the carriermidsection 1. Below the area of the slit 5 and in the area between thearched portions 7, contact arm 4 is bent in a direction opposite to thatof the arched portions 7 and extends beyond the axis of the slit 5. Thiscan best be seen by reference to FIG. 3. It will be noted from FIG. 3that the arms 4 and fingers 6 each have a cross section forming ordefining an undulating curve perpendicular to the longitudinal axis ofthe respective arm with each undulating curve including a pair of endcurves 7a. Curves 7a extend from a respective opposite edge of each armto a position intermediate the edges and each curve 7a has a radius ofcurvature, whose respective axis, indicated by dashed line 7b, islocated adjacent the respective transverse plane of the arm, whichextends along a respective opposite edge 4a and 4b. A curve 70 islocated intermediate each pair of end curves 7a. The intermediate curve70, as seen in FIG. 3, has a radius of curvature, indicated by dashedlines 7d, extending from an axis located intermediate the arms and theradius is smaller than the radius of curves 7a. The fingers 6 each havea cross section defined by a respective one of the end curves 7a andcontinuous with the respective end curve of the respective arm tostiffen the fingers. When a male contact member is received between thearms 4, as indicated by dashed lines 7e, the curved portions 7a provideat least two points of engagement between each arm 4 and the pin orblade contact, despite considerable variations in dimensionaltolerances.

In order to strengthen the mid-section l of the contact, a depression ordimple 8 is formed on the rear side of the contact. The dimple 8 makesrigid the otherwise resilient ridge 2.

A resilient catch 9 is provided on the carrier midsection 1 so that thedownwardly bent end of catch 9 can be pressed into the U-shaped carriermid-section 1 upon insertion of the contact in a terminal block.

FIG. 1 shows that the ridge 2 is provided with Wings 10 extending alongboth sides of ridge 2. At least one of the edge sections is providedwith a stop shoulder 11.

The furcate contact of FIGS. 4 and 5 differs from the embodiment shownin FIGS. l-3 in the shape of the carrier mid-section 1 and the ridge 2.The other parts of the contact are unchanged and are denoted by the samereference symbols as in FIGS. l-3. No protruding edges are provided atthe ridge 2. However, the U- shaped carrier mid-section l is providedwith protruding lugs 13 in the area adjacent the ridge 2. At least oneof the lugs I3 is provided with a stop shoulder 11.

From the foregoing, it can be readily realized that this invention canassume various embodiments. Thus, it is to be understood that theinvention is not limited to the specific embodiments described herein,but is to be limited only by the appended claims. For example, it iswithin the scope of this invention that the contact arms 4 not beprovided with slits 5 and that each contact arm 4 may only have a singleconcavely arched portion 7. Further, two parallel concavely archedportions 7 can be provided in each arm 4 without a slit 5. The carriermid-section 1 and the ridge 2 can have uniform cross-sections over theirentire lengths. Additionally, the carrier mid-section 1 and ridge 2 maybe U- shaped, fiat. or slightly arched, and the carrier midsection 1 maybe provided with a separate reinforcing dimple from that of the ridge 2.

What we claim is:

1. A furcate contact for establishing a plurality of electricalconnections to a male contact comprising:

a body portion including opposite edges;

a pair of cantilever spring contact arms each having an integrallyformed portion on said body portion with one surface of each integrallyformed portion lying in a respective transverse plane extending along arespective one of the opposite edges of said body portion, said armseach extending longitudinally in one direction from one end of said bodyportion toward each other arm and from the respective transverse planeto locate the ends of said arms spaced from said body portion inadjacent positions for receiving a male contact between the ends of saidarms spaced from said body portion, a pair of spaced guiding fingersformed on each end of each arm spaced from said body portion with eachpair of fingers formed in a direction extending from each other pair offingers for guiding said male contact for receipt between said arms;

each arm having a cross section defining an undulating curveperpendicular to the longitudinal axis of the respective arm with eachundulating curve including a pair of end curves with each end curveextending from a respective opposite edge of each arm and formed along aradius of curvature extending from an axis spaced adjacent a respectivetransverse plane; each finger having a cross section defined by andcontinuous with a respective one of said end curves defining the crosssection of a respective arm; and

a curve for each arm intermediate each pair of end curves with eachintermediate curve formed along a radius of curvature having an axisintermediate said armswhereby said arms and fingers are substantiallyrigidified and the end curves of each arm provide at least two positionsof engagement with said male contact for establishing a plurality ofelectrical connections to said male contact in response to the receiptof said male contact between said arms.

2. A furcate contact as claimed in claim I in which each guiding fingerextends toward the respective transverse plane with the angle betweensaid fingers less than and each intermediate curve has a radius ofcurvature smaller than the'radius of curvature of the respective endcurves.

1. A furcate contact For establishing a plurality of electricalconnections to a male contact comprising: a body portion includingopposite edges; a pair of cantilever spring contact arms each having anintegrally formed portion on said body portion with one surface of eachintegrally formed portion lying in a respective transverse planeextending along a respective one of the opposite edges of said bodyportion, said arms each extending longitudinally in one direction fromone end of said body portion toward each other arm and from therespective transverse plane to locate the ends of said arms spaced fromsaid body portion in adjacent positions for receiving a male contactbetween the ends of said arms spaced from said body portion, a pair ofspaced guiding fingers formed on each end of each arm spaced from saidbody portion with each pair of fingers formed in a direction extendingfrom each other pair of fingers for guiding said male contact forreceipt between said arms; each arm having a cross section defining anundulating curve perpendicular to the longitudinal axis of therespective arm with each undulating curve including a pair of end curveswith each end curve extending from a respective opposite edge of eacharm and formed along a radius of curvature extending from an axis spacedadjacent a respective transverse plane; each finger having a crosssection defined by and continuous with a respective one of said endcurves defining the cross section of a respective arm; and a curve foreach arm intermediate each pair of end curves with each intermediatecurve formed along a radius of curvature having an axis intermediatesaid arms whereby said arms and fingers are substantially rigidified andthe end curves of each arm provide at least two positions of engagementwith said male contact for establishing a plurality of electricalconnections to said male contact in response to the receipt of said malecontact between said arms.
 2. A furcate contact as claimed in claim 1 inwhich each guiding finger extends toward the respective transverse planewith the angle between said fingers less than 180* and each intermediatecurve has a radius of curvature smaller than the radius of curvature ofthe respective end curves.